Study: Earth's CO2 level already dangerous

NEW YORK, Nov. 11 (UPI) -- A U.S.-led group of scientists says if climate disasters are to be averted, carbon dioxide levels must be reduced below the levels that already exist.

The group of 10 scientists from the United States, Britain and France said it concluded an optimum CO2 level would be less than 350 parts per million. Earth's current atmospheric CO2 level is 385 ppm and is increasing by about 2 ppm annually.

"This work and other recent publications suggest we have reached CO2 levels that compromise the stability of the polar ice sheets," said Yale University Professor Mark Pagani, "How fast ice sheets and sea level will respond are still poorly understood, but given the potential size of the disaster, I think it's best not to learn this lesson firsthand."

The lead author of the study, Adjunct Professor James Hansen of Columbia University, said there is a bright side to the study's conclusions.

"Following a path that leads to a lower CO2 amount," said Hansen, "we can alleviate a number of problems that had begun to seem inevitable, such as increased storm intensities, expanded desertification, loss of coral reefs and loss of mountain glaciers that supply fresh water to hundreds of millions of people."

The research appears in the Open Atmospheric Science Journal.